The primary goal of this proposal is to adopt a multi-disciplinary approach towards the discovery and characterization of novel small molecules that target allosteric surface cavities of procaspases 3, 7 and 9 in order to elicit agonistic activity. Ideally, intracellular small molecule activators of these "effector" procaspases will then promote cellular apoptosis in lieu of the normal, highly-controlled proteolytic activation by upstream "initiator" caspases, or incorporation into the apoptosome. Identification and characterization of these allosteric sites and corresponding agonists with high throughput screening and fragment-trapping will further elucidate the structural rearrangements that occur upon activation in the absence of proteolytic cleavage of caspases 3 and 7. Furthermore, these results will shed light on the activation mechanism of procaspase 9 during assembly of the apoptosome complex. The ultimate goal is to identify novel mechanisms and lead compounds that promote apoptosis in tumor cells as a major first step towards caspase-directed chemotherapeutic therapies. The potential benefits to apoptosis regulation by procaspase activation will also have significant rewards in the development of novel methods to target proteins for drug discovery. [unreadable] [unreadable] [unreadable]